Driver for mounting a multiple sprocket arrangement to a bicycle

ABSTRACT

A multiple sprocket arrangement is mountable to a rear axle arrangement of a bicycle. The multiple sprocket arrangement includes a sprocket assembly having a plurality of sprockets with different numbers of teeth. The sprocket assembly includes a support ring integrated with at least a largest sprocket of the plurality of sprockets. The support ring is firmly connected to the remaining sprockets and has a torque transmitting section.

This application claims the benefit of U.S. patent application Ser. No.15/681,753, filed on Aug. 21, 2017, which claims the benefit of U.S.patent application Ser. No. 13/549,197, filed on Jul. 13, 2012, whichclaims priority to German Patent Application No. DE 102012006771.2,filed on Apr. 3, 2012 and German Patent Application No. DE102011107162.1, filed on Jul. 13, 2011.

BACKGROUND OF THE INVENTION

The present invention relates to a driver for attaching a multiplesprocket arrangement having a plurality of sprockets with differentnumbers of teeth to a rear axle of a bicycle. The present inventionrelates in particular to a driver that is attachable to the sprocketassembly in a torque-transmitting manner, and an adapter, which may becoupled to the driver, wherein the sprocket assembly may also includesprockets having a smaller inner diameter or dedendum circle than theouter diameter of the driver, and wherein the sprocket assembly in theregion of the sprockets with smaller diameter may be connected to thedriver via the adapter.

Various systems are known in the prior art for the attachment ofmultiple sprocket arrangements to rear axles. Typically, a driver issupported in a rotatable manner on the rear axle of a bicycle via abearing arrangement. The driver is in torque-transmitting engagementwith the hub shell via a one-way clutch and permits a torquetransmission in the one direction of rotation (drive direction), whereasit is decoupled from the hub shell with respect to rotation in otherdirection in order to provide a freewheel. Typically, an outercircumferential surface of the driver is provided with a splinedconfiguration or a similar profile in order to allow individualsprockets, or an assembly composed of several sprockets, to be mountedthereon so as to transmit torque. A solution of this type is shown inthe prior art, for example, in DE 199 15 436 A1. Comparable solutionsare further shown in documents JP 59-165293, GB 2 177 628 A or EP 0 277576 A2. Another known solution is described in EP 1 342 657 B1. Itdiscloses a possibility of attaching sprockets with a smaller diameterto a driver. Although this system is widely used, it is increasinglyreaching its limits and has some disadvantages. For example, the numberof sprockets is continually increasing, particularly on high-end bicycleshifting systems now being used by both professional cyclists andrecreational cyclists. Here both relatively large increments, but alsoespecially relatively small increments are often being used so as toprovide, for example, the optimal gear ratio when covering flat terrainor when riding in a group at a constant cadence. In both cases, i.e.,whenever small increments with small jumps in gearing are provided, orwhenever large jumps in gearing need to be available, there is anincreasing need for very small sprockets, i.e. sprockets with 10 teethor less. Such small sprockets, however, cannot be mounted on a driver ofthe conventional type, and thus resulting in additional parts beingnecessary which have a complicated structure or are difficult toinstall. Small-diameter sprockets specifically require relativelycomplex carrier profiles. Overall, particularly with the adaptersolution shown in the prior art, the problem arises that a multiplicityof different parts is necessary, which are complicated to install andentail a relatively heavy weight.

Another disadvantage of this solution from the prior art is that themulti-part arrangement requires the outer bearing be further inward thanthe driver in the axial direction. This means that when the bicyclechain engages the smallest sprocket, there is a relatively large axialdistance between the location of the chain engagement and the locationof torque transmission and the bearing. This results in undesirablemechanical stresses and a less-effective power flow.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a driver for amultiple sprocket arrangement of the type mentioned above with anadapter mountable to a rear axle arrangement which takes into accountthe problems described above and which has a simple design with reducedweight.

In contrast to the prior art, in which all sprockets generally actdirectly or indirectly via corresponding external splines on the driver,it was realized with the present invention that the entire driver doesnot need to be provided with corresponding external splines, but thatsections in the external region of the driver can also be used to fix anadapter which attaches the sprocket assembly at least axially. Thetorque transmission between the sprocket assembly and the driver canoccur spatially away from the coupling section. The adapter ispreferably used solely for fixing the sprocket assembly in the axial andradial direction. This has the advantage that the sections of thesprocket assembly used for torque transmission can be designedspecifically for this purpose and the sections used for axial and radialfixing via the adapter can be coordinated accordingly with the demandsfor axial fixing.

Furthermore, the variability for the use of different sprocketassemblies is increased by the respected adaptation of the adapter. Acorresponding sprocket assembly needs only to be provided with thesuitable torque transmission section and then can be axially fixed withan adapter correspondingly adapted to the sprocket assembly, wherein theadapter engages the coupling sections of the driver. This makes itpossible to use even sprocket assemblies with very small sprockets,which cannot be combined with conventional drivers at all, or only withconsiderable technical effort.

The present invention provides a driver for mounting a multiple sprocketarrangement to a bicycle rear axle arrangement. The multiple sprocketarrangement includes a sprocket assembly having a plurality of sprocketswith different numbers of teeth and an adapter. The rear axlearrangement includes a hub. The driver includes an input torquetransmitting profile for transmitting torque between the sprocketassembly and the driver, a positioning section positioning the sprocketassembly in the radial direction, external thread for threadablyreceiving the adapter and an output torque transmitting arrangement fortransmitting torque between the driver and the hub. The external threadis disposed between the input torque transmitting profile and thepositioning section.

In one embodiment of the present invention, the driver includes a guidesection arranged between the input torque transmitting profile and thepositioning section. The guide section does not need to transmit forces,moments or any tensile stresses and therefore can be a thin wall,resulting in a light weight driver. Another advantage of the guidesection is that it provides a reliable and fault-free assembly of theadapter on the driver. The guide section guides the adapter while it isbeing screwed on the external thread of the driver, preventing theadapter from being tilted and screwed on in a faulty manner, reducingthe possibility that the external thread on the driver or the internalthread on the adapter could be damaged.

The external thread of the driver may be directly adjacent the inputtorque transmitting profile so that those regions in which moments andtensile stresses occur are locally concentrated and the driver can bemade stronger in these loaded regions. The other regions of the driverthat are not loaded can have a thinner wall.

In another embodiment of the present invention, the driver includes anaxial stop for axially positioning the sprocket assembly on the rearaxle arrangement. The axial stop is adjacent the input torquetransmitting profile.

Further, the axial stop may be disposed adjacent the external thread andthe input torque transmitting profile resulting in the forces andmoments being locally concentrated.

In another embodiment of the present invention, the input torquetransmitting profile extends only over a partial section of the axiallength of the driver between the axial stop and a free end of thepositioning section, preferably over a partial section that is smallerthan a quarter, most preferably smaller than a fifth of the axial lengthof the driver. The input torque transmitting profile does not have toextend over the entire length or most of the length of the driver but itis sufficient that the axial length of the input torque transmittingprofile correspond to the axial length of a corresponding torquetransmitting profile of the sprocket assembly.

In another embodiment of the present invention, the extemai thread aredirectly adjacent the input torque transmitting profile. Axial forcesthat occur between the stop and the external thread used for engagingwith the adapter, can thus be concentrated on a relatively short axialsection, instead of transmitting them over a longer axial section.Furthermore, this arrangement of the external thread provides theadvantage that bearing surfaces or section in which bearings have to beaccommodated, do not axially overlap with the external thread. Theytherefore remain uninfluenced by the external thread.

In another embodiment of the present invention, the guide section of thedriver includes a cylindrical outer surface that is solid or providedwith weight-saving openings. In this embodiment of the driver, it ispossible to design the guide section specifically for its function ofguiding the adapter during its assembly in order to avoid a faultyassembly, in which, for example, the external thread on the driver orthe thread on the adapter are damaged. An optimum positioning of thesprocket assembly on the driver can be achieved by using the guidesection. The guide section may have a smaller maximum outer diameterthan the maximum outer diameter of input torque transmitting profile orthe external thread. The positioning section may have a distal enddistant from the input torque transmitting profile. The positioningsection has a smaller outer diameter than the outer diameter of theguide section. The smaller outer diameter of the guide section allowsvery small sprockets to be provided on the multiple sprocketarrangement, which is often problematic with conventional drivers. It isthereby possible for the smaller-diameter guide section to accommodate abearing. If a larger bearing is needed to absorb greater loads, anenlarged inner diameter section may be provided on the driver at adistal end from the input torque transmitting profile.

In another embodiment of the invention, the positioning section formspart of the outer circumference of the bearing projecting axially out ofthe driver. In other words, it can thus be provided that the driver isembodied on its end distant from the input torque transmitting profilewith an inner diameter for accommodating the bearing, which is embodiedto be so large that in contrast to other embodiments a positioningsection integrally embodied on the driver is completely omitted. Thebearing partially accommodated in the driver and partially projectingaxially therefrom forms with its outer bearing bushing a protrudingsection, which then is used as a positioning section. This has theadvantage that the precisely produced outer surface of the outer bearingbushing of the bearing partially projecting out of the driver can beused as a positioning section embodied in a geometrically exact manner.Further, the driver has a proximal end near the input torquetransmitting profile having an inner diameter section for accommodatinga bearing.

In another embodiment of the invention, the sprocket assembly ispreassembled as an interconnected assembly and can be connected to thedriver by the adapter, wherein the adapter includes a first couplingsection by which it can be installed on the driver, and includes asecond coupling section by which it is coupled to the preassembledsprocket assembly. In contrast to the prior art, the sprocket assemblymay be preassembled and thus is easier to handle as a whole duringassembly. This also enables the adapter to be significantly simplified.The adapter can then be designed so it does not have to receive orprovide the bearing support for individual sprockets or a subassembly ofindividual sprockets. Instead, the adapter provides only the function ofprimarily axial (and optionally radial) fixing of the sprocket assemblyon the driver. Since the sprocket assembly is self-supporting, as itwere, it does not need to be additionally supported via the adapterrelative to the driver, as is the case in the prior art with systemsthat require the assembly and fixing of individual sprockets or sprocketgroups. Naturally, within the scope of the invention advantageouslydrivers specifically coordinated with the adapter (as described above)are preferably used compared to conventional drivers.

The torque transmission from the sprocket assembly to the driver canalso be designed in a much simpler manner than is the case with amulti-part solution with in part individual sprockets. The adapter cantherefore be designed functionally precisely for the singular functionof the positioning and fixing of the sprocket assembly in the axialdirection and in the radial direction relative to the driver, whichpermits a weight optimization. As a result, the adapter or componentsassociated with it can be provided, for example, with mating surfacesthat position the sprocket assembly in a defined location relative tothe driver in the axial and/or radial direction. Conicities can also beformed on the adapter that provide centering and clamping when theadapter is screwed in place. The transmission of torque between thesprocket assembly and the driver can be effected independently of theadapter at a different location on the sprocket assembly.

In particular it can be provided that the adapter includes in the regionof its first coupling section and/or in the region of its secondcoupling section with a mating surface for radial and/or axialpositioning relative to the sprocket assembly and to the driver. It isthereby possible that the mating surface is a plastic body attached tothe adapter, for example, a plastic ring. The plastic ring may be moldedonto the adapter. In this context it can furthermore be provided thatthe adapter is provided with local openings, wherein the plastic massextends through these local openings. This embodiment ensures a reliablefixing of the plastic body to the adapter and ensures that on both sidesof the adapter, i.e., on the inner circumferential surface and on theouter circumferential surface, a corresponding plastic ring withsuitable mating surfaces can be embodied.

The present invention obviates the need for various different functions,such as those handled by the prior art as set forth in EP 1 342 657 B1by the adapter or by complex intermediate sprockets mounted on theadapter, specifically, the positioning and torque transmittingaccommodation of individual sprockets of small diameter. In overallterms, this results in a considerably simplified system that is clearlyoptimized in terms of saving weight.

In one embodiment of the present invention, the adapter is a steppedtubular sleeve having a first coupling section with a first outerdiameter and a second coupling section having a second outer diametersmaller than the first outer diameter. The first outer diameter ismatched to the diameter of the driver, while the second outer diameteris matched to the smaller-diameter regions of the sprocket assembly.Thus, a solid, heavy adapter can be avoided.

In this embodiment of the present invention, the first coupling sectionmay include internal thread that engages the external thread of thedriver. Thus the adapter can be screwed onto the driver which provides areliable permanent retention during assembly. Further, the driver andthe adapter respectively may have mating surfaces which with mutualabutment in the assembled state define a predetermined relative positionin the axial direction and/or in the radial direction (centering)between the driver and adapter. The second coupling section may includeexternal thread for attaching the sprocket assembly to the adapter. Theattachment can be effected, for example, by an additional nut that canbe screwed onto the external thread on the second coupling section ofthe adapter and engages the sprocket assembly to provide positioning andmounting in place.

As an alternative to a screw-on attachment between the adapter and thesprocket assembly, it is also possible to associate the adapter directlywith the sprocket assembly, for example, to mount it on the assembly bya frictional-locking or positive-locking engagement. In thisconfiguration, the second coupling section includes at least oneretaining projection that engages a corresponding retaining recess onthe sprocket assembly. The adapter is thus attached to the sprocketassembly by a type of latching. The interaction between the retainingprojection and the retaining recess can be realized via an undercut.This embodiment has several advantages. The sprocket assembly no longerneeds to be axially fixed with an additional lock nut on the smallestsprocket. It should be noted that in the prior art relatively highcontact forces existed with the axially fixing of the smallest sprocketwhich is why the entire sprocket assembly or parts thereof have to berelatively solid and heavy. The interaction between the retainingprojection and the retaining recess allows the sprocket assembly to bemore effectively sized, and in particular, the assembly must only bedesigned with the appropriate strength in that area where the contactforces actually have an effect, i.e., in the area of the retainingformation.

In this connection, provision can be made whereby the retainingprojection is disposed on an axial end of the adapter. The axial endincluding a plurality of slots to create latching tabs. This enables theadapter to be plugged into the sprocket assembly and latched into placesuch that during the latching action the latching tabs can flexelastically radially inward due to the axial slot formation and thenengage behind the retaining recess in a latching action. In other words,provision may be made whereby the latching tabs are designed to snapinto the retaining recess. The action of snapping in place can beassisted by providing the latching tabs with lead-in chamfers.

In order the install the adapter more easily, the adapter includes atorque-transmitting tool interface for receiving a tool. Thetorque-transmitting interface may be disposed directly on the adapter oron a mounting ring that can be coupled to the adapter in atorque-transmitting manner. In the first alternative, it is thuspossible to provide a radial splined configuration or an end splinedconfiguration or another type of mechanical engagement profile directlyon the adapter. In both cases, a mounting tool can be engaged with therespective torque transmitting tool interface.

When a separate mounting ring is provided, the mounting ring includesradial projections that engage the axial slots between the latching tabsso as to transmit torque. The mounting ring is thus coupled with theadapter in a torque-transmitting manner.

With respect to the mounting ring, it is further possible according tothe invention that this is provided with mating surfaces for the radialand/or axial positioning of the sprocket assembly relative to thedriver. Unlike the above-described embodiments, the radial and/or axialpositioning of the sprocket assembly can be effected either completelyor partly by the mounting ring.

The sprocket assembly may include a support ring coupled to the driverto transmit torque between the sprocket assembly and the driver. Thissupport ring specifically can be of correspondingly solid constructionin order to be able to handle the demands of transmitting torque to thedriver. The rest of the sprocket assembly can then be embodied in acorrespondingly lighter manner. One or more end sprockets can be formedon or mounted on the support ring.

A tubular element may be provided as an axial stop between the supportring and the adapter. This tubular element functions in certainembodiments as an axial stop for the adapter or for the sprocketassembly during the coupling with the driver. This can prevent thesprocket assembly itself from being over-tightened and thus undesirablydeformed.

In another embodiment of the present invention, the adapter surrounds atleast one bearing accommodated in the driver. The bearing can also beplaced in the adapter, wherein the adapter is then screwed into thedriver by external thread, or can be screwed onto the driver by internalthread.

These and other features and advantages of the present invention will bemore fully understood from the following description of one or moreembodiments of the invention, taken together with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a cross-sectional view of a multiple sprocket arrangementaccording to one embodiment of the present invention;

FIG. 2 is a cross-sectional view of an adapter of the multiple sprocketarrangement of FIG. 1;

FIG. 3 is a cross-sectional view of a driver of the multiple sprocketarrangement of FIG. 1;

FIG. 4 is a perspective view of the driver of FIGS. 1 and 3;

FIG. 5 is a cross-sectional view of a multiple sprocket arrangementaccording to another embodiment of the present invention;

FIG. 6 is a cross-sectional view of an adapter of the multiple sprocketarrangement of FIG. 5;

FIG. 7 is a perspective view of the adapter of FIGS. 5 and 6;

FIG. 8 is a cross-sectional view of a driver of the multiple sprocketarrangement of FIG. 5;

FIG. 9 is a perspective view of the driver of FIGS. 5 and 8;

FIG. 10 is partial cross-sectional view of a multiple sprocketarrangement according to another embodiment of the present invention;

FIG. 11 is a cross-sectional view of an adapter of the multiple sprocketarrangement of FIG. 10;

FIG. 12 is a cross-sectional view of a mounting ring of the multiplesprocket arrangement of FIG. 10;

FIG. 13 is a front view of the mounting ring of FIGS. 10 and 12;

FIG. 14 is a cross-sectional view of a driver of the multiple sprocketarrangement of FIG. 10;

FIG. 15 is a cross-sectional view of a rear axle arrangement accordingto one embodiment of the present invention;

FIG. 16 is a perspective view of a driver of the rear axle arrangementof FIG. 15;

FIG. 17 is a cross-sectional view of the driver of FIGS. 15 and 16;

FIG. 18 is a cross-sectional view of an alternative embodiment of thedriver of FIG. 17 that accommodates a larger bearing;

FIG. 19 is a partial cross-sectional view of a multiple sprocketarrangement according to another embodiment of the present invention;

FIG. 20 is a cross-sectional view of an adapter of the multiple sprocketarrangement of FIG. 19;

FIGS. 21 and 22 are cross-sectional views of the adapter of FIG. 19; and

FIG. 23 is a cutaway perspective view of the adapter of FIG. 19.

DETAILED DESCRIPTION

FIG. 1 shows a multiple sprocket arrangement 10 mountable to a bicyclerear axle arrangement according to one embodiment of the invention.

The multiple sprocket arrangement 10 generally includes a sprocketassembly 12, a driver 16 and an adapter 26. The sprocket assemblyincludes a plurality of sprockets 141 through 1410 having differentdiameters and different numbers of teeth. The sprocket assembly may beone piece or a cohesive assembly which can be preassembled as onecomponent during assembly. Even if the sprocket assembly 12 includesseveral individual parts, these are firmly connected after assembly andform a self-supporting unit.

The sprocket assembly 12 is coupled to the driver 16 which is shown indetail in FIGS. 3 and 4. The driver 16 is mounted to the to a rear axleof the rear axle arrangement in a known manner. In the region 18 anarrangement may be attached for transmitting the torque from the driver16 or the sprocket assembly 12 to a freewheel device 7 and therefrom toa hub body 8 (see FIG. 15) of the rear axle arrangement 9. The driver 16includes an input torque transmitting profile or splines 17 fortransmitting torque from the sprocket assembly 12. The driver 16includes an axial stop or an annular radial projection 19 with an axialface 21 that is used to axially position the sprocket assembly 12.

On its right end in FIG. 1, the driver 16 includes a section 20 reducedin its outer diameter. The section 20 includes external thread 22 thatend in a shoulder 24 and a positioning section or an outercircumferential surface 25 which forms a mating surface. The section 20is threadably connected to the adapter 26 which is shown in detail inFIG. 2. The adapter 26 includes first coupling section 28 having a largediameter and internal thread 30. An inner circumferential surface 29adjoins the internal thread 30. The inner circumferential surface 29forms a mating surface that mates with the positioning section or theouter circumferential surface 25 of the driver 16 to radially positionthe adapter 26 relative to the driver 16.

The first coupling section 28 ends in a front face 32, which in theassembled state shown in FIG. 1 abuts the shoulder 24 and thusdetermines the axial position of the adapter 26 relative to the driver16. The adapter 26 furthermore has a second coupling section 34, whichhas a smaller diameter than the first coupling section 28. The first andsecond coupling sections 28 and 34 are connected to one another via atransition section 36.

The second coupling section 34 includes external thread 38. In theassembled stated according to FIG. 1, a lock nut 40 is screwed onto theexternal thread 38. The lock nut 40 has on its outer circumferentialsurface several recesses 42, on which a tool may engage in order toexert a torque on the lock nut for bracing during the assembly. The locknut 40 has a lateral mounting surface 44 that bears against an axial endsurface 46, facing towards it, of the sprocket assembly 12. Bytightening the lock nut 40, the sprocket assembly 12 can be positionedand fixed in the axial direction.

In FIG. 1, a tubular element 50 includes one end 52 supported axially ona support ring 54 of the sprocket assembly 12 and another end 56disposed inside the sprocket assembly 12 on one of the smallersprockets, namely on the sprocket 14 ₂ The power flow applied by thetightening of the lock nut 40 in the axial direction thus extends overboth the small sprockets 141 and 14 ₂, the tubular element 50 on thesupport ring 54 and from this into the driver 16.

The sprocket assembly 12 includes the separate support ring 54, on whichthe largest sprocket 14 ₁₀ is integrally connected to and a subassemblyof the remaining sprockets 141 through 14 ₉ as well as the tubularelement 50 which is inserted before the attachment of the support ring54. The support ring 54 is firmly connected to the subassembly of theremaining sprockets 14 ₁ through 14 ₉, for example, by molding,riveting, adhesion or the like. The support ring 54 has a torquetransmission section having splines that corresponds to the input torquetransmitting profile or splines 17 on the driver 16 to transfer torquebetween the sprocket assembly 12 and the driver 16.

FIG. 1 also shows a bearing 55 arranged in the driver 16 in a bearingrecess having a mating surface 57 in a precisely fitting manner and isprovided for the bearing of the driver 16 on the rear axle (not shown).

The assembly of the entire system is relatively simple. The adapter 26shown in FIG. 1 is screwed onto the driver 16 and fixed. Then thesprocket assembly 12 is pushed onto the driver 16. Finally, the lock nut40 is screwed on and tightened until the tubular element 50 serves as adefined stop.

Overall a system thus results that is considerably simplified comparedto the prior art, which can be embodied in a substantially lightermanner than, for example, the complex multi-part system according to theclosest prior art. However, this system can be combined with existingdriver solutions long in use, so that sprocket assemblies with sprocketswith very low numbers of teeth can also be placed on such driversaccording to the prior art.

FIGS. 5-9 show another embodiment of the present invention. To avoidrepetitions, the same reference numbers are used for the same type ofcomponents or components with the same action as in the previousembodiment. Only the differences from the previous embodiment are dealtwith below.

Again it can be seen that external thread 22 are attached to the driver16. A section 20 is free from thread adjoining the external thread 22.The adapter 26 includes a section 28 having internal thread 38. Incontrast to the previous embodiment depicted in FIG. 1, the adapter 26is supported with its front face 32 in the axial direction not on thedriver 16 but on the tubular element 50 (see FIG. 5).

Another difference between the previous embodiment and this embodimentis how the adapter 26 is coupled to the sprocket assembly 12. Theadapter 26 includes a retaining projection or section 60 having a largerdiameter with an outer circumferential mating surface 61 for radialpositioning and a shoulder-like mating surface 62. The section 60engages a retaining recess or a radial recess 64 in the sprocketassembly 12, which forms an undercut. The mating surface 62 bearsagainst a corresponding mating surface 66 to ensure that the sprocketassembly 12 in the assembled state cannot slip over the mating surface62 in the axial direction. With the bracing of the sprocket assembly 12with the driver, the clamping forces act at this point. This is betterfor the power flow than with the prior art, in which the sprocketassembly is tightened with a clamping element on the driver on thesmallest sprocket, which leads to unfavorable high clamping forces onthe smallest sprocket. It should be noted that the adapter 26 is notpressed in the radial recess 64, but is accommodated therein with slightplay so that the adapter 26 can be rotated relative to the sprocketassembly 12.

An inner circumferential mating surface 65 arranged to increase theelasticity of the adapter at a distance a from the mating surface 61interacts with a corresponding outer circumferential mating surface 67of the driver 16 (see FIG. 8) for radial positioning. A slight conicity69 is arranged outwardly of the outer circumferential mating surface 67.

An additional difference between the embodiments is that the externalthread on the second coupling section 34 of the adapter 26 areeliminated because the lock nut is no longer necessary. However, theadapter 26 has on the second coupling section 34 a torque-transmittingtool interface or projections 68 extending radially inwards forreceiving a tool for assembly purposes.

In this embodiment, the sprocket assembly includes the support ring 54that is integral with the largest sprocket 14 ₁₀ (end sprocket), thesubassembly of the sprockets 14 ₁ through 14 ₉, the tubular element 50inserted in advance and the adapter 26 inserted in advance. Thisarrangement is pushed onto the driver 16 and fixed by screwing theadapter 26 with its internal thread 38 onto the external thread 30 ofthe driver 16. With this screwing, the adapter 26 rotates relative tothe subassembly of the sprockets 141 through 149.

The result is thus a design that is relatively simple, and, inparticular, extremely easy to assemble. Both embodiments have theadvantage that a sprocket assembly with very small sprockets and thuslow numbers of teeth can be used. The embodiment according to FIGS. 5-9has the further advantage that the use of a lock nut is no longernecessary, resulting in contact forces no longer acting on the smallestsprocket, which could impair the sprocket's elasticity when transmittingforce from the chain. Moreover, due to the omission of the lock nut,practical disadvantages associated therewith can be avoided, such as thenecessity of additional installation space for the lock nut.

Furthermore, an undesirable interaction of an assembly tool insertedinto the outer profile of the lock nut with the teeth of the sprocketduring the assembly or in operation an undesirable interaction of theouter profile of the lock nut with the chain bearing against thesmallest sprocket can be avoided.

FIGS. 10-13 show another embodiment of the present invention, which isbased on the embodiment of FIGS. 5-9. The differences between thisembodiment and the embodiment of FIGS. 5-9 are described below.

The driver 16 according to the this embodiment is similar to the driverof the embodiment of FIGS. 5-9, except the external thread 22 areshifted further to the left in the axial direction. The fundamentaldifferences are in the embodiment of the adapter 26 and in theattachment of an additional mounting ring 70.

The adapter 26 has internal thread 30 on its first coupling section 28.The adapter 26 is tubular and has only slight diameter differences. Onits right end in FIG. 11 it has a circumferential projection 60 with amating surface 62 and a circumferential chamfer 63. It can be seen inFIG. 11 that the adapter 26 includes on its axial end a plurality ofaxial slots 72, which pierce the adapter radially beyond thecircumferential projection 60 and thus create individual latch tabs 74.Due to the axial slots 72, the latch tabs 74 can yield elasticallyradially inwards. The latch tabs 74 are provided with a circumferentialchamfer 75 in order to facilitate the latching operation.

FIGS. 12 and 13 show the mounting ring 70 that includes two annularsections 80 and 82, which are connected to one another via a connectionsection 84. The outer annular section 80 has external splines thatinclude radially protruding projections 86 around its outercircumference. The number and the sizing of the projections 86 and thearrangement thereof is coordinated exactly with that of the slots 72 inthe adapter 26 so that the mounting ring 70 can be inserted into theadapter 26 such that the projections 86 engage into the slots 72 more orless precisely. However, a radial play 88 (see FIG. 10) is producedbetween the mounting ring 70 and the inner circumferential surface ofthe tabs 74 in order to ensure that the tabs 74 can yield elasticallyradially inwards. On the inner circumferential surface, the mountingring 70 has splines 68, as has already been explained with reference toFIG. 5.

The inner circumferential surface 89 of the outer annular section 80 isa mating surface that is provided for the radial positioning of themounting ring 70 relative to the driver. It rests in a fitted manner onthe outer circumferential surface 25 on the section 20 of the driver 16.

The inner annular section 82 of the mounting ring 70 is provided with amating surface 91, which interacts in a positioning manner with an innercircumferential surface 93 on the sprocket assembly 12 for radialpositioning. Moreover, a mating surface 95 is provided on the innerannular section 82, which functions to axially position the sprocketassembly relative to the driver. This surface interacts with acorresponding end surface 97 of the driver 16.

The assembly of this embodiment is carried out in a similar manner tothat according to the embodiment of FIGS. 5-9. Firstly, the adapter 26is screwed onto the driver 16. Subsequently, the mounting ring 70 isinserted into the adapter 26 so that the projections 86 engage into theslots 72. Then the sprocket assembly 12 is mounted and finally latchedwith the latch tabs 74. The chamfer 63 facilitates the positioning andthe mounting. The radial play between the mounting ring 70 latch tabs 74permits a corresponding elastic deformation of the tabs 74 during thelatching.

Finally, an assembly tool can be used to act in a torque-transmittingmanner in the splines 68 on the inner circumferential surface of themounting ring 70, so that the assembly ring 70 and with it the adapter26 can be rotated for screwing the same onto the external thread 30. Thesprocket assembly 12 can thus be mounted in the axial direction on thedriver 16, whereby the corresponding axial forces via the interaction ofthe two surfaces 62 and 66 takes place between the adapter 26 and thesprocket assembly 12.

FIGS. 15-17 show a further embodiment of the invention, wherein in turnfor the same type of components or components with the same action thesame reference numbers are used as in the preceding description of theexemplary embodiments according to FIGS. 1-14.

The embodiment according to FIGS. 15-17 includes a driver 16 that isparticularly advantageous, which is supported on an axle 11. This driver16 includes the axial stop or annular radial projection 19 with itsaxial face for the axial positioning of the sprocket assembly 12. Theinput torque transmitting profile or external splines 17 for the torquetransmission between the sprocket assembly 12 and the driver 16 extendsover a relatively short longitudinal section directly adjoining theradial projection 19. The external thread 22 extends adjacent to theexternal splines 17. The arrangement of the driver 16 according to theembodiment according to FIGS. 15-17 is similar to the driver accordingto the embodiment according to FIG. 14. If, as is shown in FIG. 15, theadapter 26 is screwed to the sprocket assembly 12 and fixed bytightening the threaded assembly, tensile forces occur in the driver 16only in the region between the axial stop 19 due to its stop functionand the thread 22. The region in which these tensile forces occur isrelatively small in the axial direction and embodied in a stable mannerdue to the splines 17.

A relatively large-area cylindrical section 23 or guide section extendsin the axial direction adjoining the external thread 22, whichcylindrical section interacts with a corresponding cylindrical innercircumferential surface to guide the adapter 26. This section 23 is alsoused as a guide surface for the adapter 26 and the sprocket assembly 12mounted thereon during assembly. Via this guide section 23 the adapter26 can be placed securely on the drive 16 with a certain radial play andscrewed on, without a tilting of the adapter 26 relative to the driver16 or even an oblique screwing damaging the threads 22 and 30. It shouldbe noted that the driver as well as the adapter can be made oflightweight aluminum, wherein this material can be deformed relativelyeasily. The guide section 23 is advantageous for precisely this reason.The drive 16 with the shoulder 24 is embodied at the axial end of theguide section 23 and ends in the projection with reduced diameter withthe outer circumferential surface 25 or positioning section, which inturn is used for the adapter 26 as mating surface for radialpositioning.

The mating surface 57 to accommodate the radial bearing 55 is providedradially inside this region.

FIG. 18 shows an alternative embodiment to this, in which instead of ashoulder 24, a front face 24 is provided and the axial section of thedriver 16 on the axial end thereof, reduced in its outer circumferentialarea and used to position the adapter 26, was omitted. Instead theradially inner mating surface 57 was radially enlarged in order toaccommodate a bearing 55 with larger diameter, which projects out of thedriver 16 by an axial section. This projecting axial section forms withits precisely embodied outer circumferential area the mating surface 25that can be used for positioning the adapter.

FIGS. 19-23 show a further embodiment of the invention, wherein in turnthe same reference numbers were used for the same type of components orcomponents with the same action as in the preceding description of theexemplary embodiments according to FIGS. 1-18.

The embodiment according to FIGS. 19-23 corresponds essentially to theembodiment according to FIGS. 15-18 and includes an advantageouslyembodied adapter 26. This adapter 26 has in its right end region, whichin the assembled state is arranged near to the mating surface 25, aplastic body 100. This plastic body 100 provides an annular plasticsheathing 102, 104 on the outer circumferential surface as well as onthe inner circumferential surface of the adapter 26.

As can be seen in FIG. 20, the adapter 26 as a blank is embodied in aslightly conical manner in this region and has radial openings 106arranged at regular angular intervals. The two plastic rings 102, 104are located in the region of these radial openings 106. They areintegrally connected to one another by webs extending through theopenings 106. The two plastic rings 102, 104 can thus be molded onto theadapter blank according to FIG. 20 and shaped integrally on the adapter26.

The two plastic rings 102, 104 include mating surfaces 110, 112 whichextend respectively parallel to the longitudinal axis A and with an areasection orthogonally to the longitudinal axis A The mating surface 112on the inner plastic ring 104 is used for the radial and axialpositioning of the adapter 26 relative to the driver 16. The matingsurface 110 on the outer plastic ring 102 is used to position thesprocket assembly relative to the adapter 26.

The two plastic rings 102, 104 render possible with relatively littleeffort a tolerance equalization in the interface to the adjacentcomponent and the provision of suitable positioning surfaces or matingsurfaces to those components that come into contact with the adapter.

In the embodiments according to FIGS. 5-23 provide the followingadvantages over the prior art. The contact forces on the small sprocketvia a lock nut can be avoided due to the latching. The furtherdisadvantages connected to the lock nut, such as additional installationspace or an undesirable interaction with the chain or the smallestsprocket in operation or during assembly can also be avoided. Thesprocket assembly can be dimensioned in a correspondingly stable mannerin particular in the region of the latching, but in other regions can beembodied weaker and thus in a more weight-saving manner. Specialpositioning mating surfaces to the driver and to the sprocket assemblycan also be provided for centering and absorbing radial loads. Thedriver can also be markedly improved in terms of its structure and itsweight compared to the prior art. For bracing it has external thread andhas a corresponding catch profile for torque transmission also in theregion of the smaller sprockets, which avoids unfavorable tensionconditions. The arrangement of the bearing inside the sprocket assemblyis subject to far fewer restrictions. In particular the embodimentsaccording to FIGS. 15-23 are advantageous due to the advantageousconcentration of the occurring tensile forces in the region of thesplines 17 embodied in a relatively solid manner. In total, all of theexemplary embodiments of the invention create many advantages over theprior art. The individual components have been clearly optimizedcompared to the prior art and interact with their individual featuressuch that overall a lighter, more stable system that is easier toassembly results.

While this invention has been described by reference to severalembodiments, it should be understood that numerous changes could be madewithin the spirit and scope of the inventive concepts described.Accordingly, it is intended that the invention not be limited to thedisclosed embodiments, but that it have the full scope permitted by thelanguage of the following claims.

I claim:
 1. A multiple-sprocket arrangement for mounting on a rear wheelaxle arrangement of a bicycle, comprising: a sprocket assembly having aplurality of sprockets of different sizes, the sprocket assemblycomprising a torque transmitting section configured to interface with adriver and at least two sprockets having a smaller inner diameter thanan outer diameter of the driver, and an adapter designed to couple theat least two sprockets of the sprocket assembly to the driver, theadapter configured to threadably attach to the driver axially inward ofthe at least two sprockets, wherein the adapter has at least one outercircumferential retaining projection configured to secure the at leasttwo sprockets to the driver.
 2. The multiple-sprocket arrangement ofclaim 1, wherein the outer circumferential retaining projection furthercomprises a shoulder-like mating surface.
 3. The multiple-sprocketarrangement of claim 1, wherein the adapter includes atorque-transmitting tool interface.
 4. The multiple-sprocket arrangementof claim 3, wherein the torque-transmitting tool interface is disposeddirectly on the adapter.
 5. The multiple-sprocket arrangement of claim1, wherein the adapter is configured to surround at least one bearing.6. The multiple-sprocket arrangement of claim 1, wherein the adapterincludes a plastic body in an end region of the adapter.
 7. Themultiple-sprocket arrangement of claim 6, wherein the plastic body isdisposed at a mating surface of the adapter and the sprocket assembly.8. The multiple-sprocket arrangement of claim 6, wherein the plasticbody is disposed radially inward at least one sprocket of the sprocketassembly.
 9. The multiple-sprocket arrangement of claim 1, wherein thetorque transmitting section comprises splines.
 10. The multiple-sprocketarrangement of claim 9, wherein the splines are configured to interfacewith splines of the driver.
 11. The multiple-sprocket arrangement ofclaim 1, wherein the adapter is made of aluminum.
 12. Themultiple-sprocket arrangement of claim 1, wherein the plurality ofsprockets includes a small sprocket having ten (10) or fewer teeth. 13.The multiple-sprocket arrangement of claim 12, wherein the smallsprocket is one of the at least two sprockets having a smaller innerdiameter than the outer diameter of the driver.
 14. Themultiple-sprocket arrangement of claim 1, wherein the sprocket assemblyis configured to transmit all torque applied to the plurality ofsprockets through the torque transmitting section.
 15. Themultiple-sprocket arrangement of claim 1, wherein the remainingsprockets of the plurality of sprockets number at least eight (8). 16.The multiple-sprocket arrangement of claim 1, wherein the sprocketarrangement further comprises an inner circumferential surfaceconfigured to mate with a surface of the adapter to radially positionthe sprocket assembly.